KiOR says it has no other sources of near-term financing, and would need more money by Aug. 21 even with Khosla’s infusion.

“We have substantial doubts about our ability to continue as a going concern,” the company said in an SEC filing that also warns it could be forced into bankruptcy if it doesn’t sort out its finances soon.

That outcome could be a serious blow for a technology that green energy advocates have viewed with much optimism. The company had developed a process to transform plants into fuel suitable for use in vehicles.

While other biofuels are made from plants — ethanol from corn and sugarcane, biodiesel from vegetable oil – KiOR’s focus is on vegetation that doesn’t compete as a food sources.

Advocates for the technology say the materials KiOR uses don’t require as much fertilizer as edible plants, which reduces greenhouse gas emissions associated with producing the fertilizer or tending the crops.

That gives it an environmental advantage over ethanol made from corn, said Bruce Dale, a professor at Michigan State University who is a biofuels expert.

Some plants used in cellulosic fuels also can grow on land not suitable for other crops.

And it has announced it probably will default on the $69.4 million balance outstanding on a loan from the state of Mississippi.

Justin Jenkins, a research associate at Raymond James & Associates, said few if any other players in the U.S. have produced cellulosic fuel in the volume that KiOR did, and the Columbus facility was one of the first big tests for such fuel production in the U.S.

He said KiOR’s trouble doesn’t signal the end of investment in cellulosic fuel, but acknowledged “it’s certainly not a helpful headline.”

“Things already weren’t great from the cellulosic perspective,” Jenkins said, calling the shutdown of the Columbus facility “disappointing, at best, in terms of the original expectations.”

Analysts note that cellulosic biofuels have taken off more slowly than expected, because of both technical and financial challenges. Corn ethanol plants typically are more economical to build and operate.

Pilot facility

KiOR opened a pilot facility in Pasadena in 2008 and a larger demonstration unit in 2010.

But the company concedes it hasn’t been able to produce cellulosic fuel consistently on a commercial scale at the Columbus plant.

KiOR produced 894,000 gallons last year, but the company has said the plant has an annual capacity of more than 13 million gallons.

Jenkins summarized the company’s dilemma: It needs production data from the plant to secure financing, but it can’t run the plant without more money. “That’s almost a chicken-and-egg,” Jenkins said.

KiOR officials, through a spokesperson, declined an interview request. But in a statement, the company rejected the notion that its financial hurdles could be evidence that cellulosic fuel isn’t viable.

“Creating a first-of-its- kind technology and a cellulosic hydrocarbon fuel is a difficult thing to do, and we have made good progress to date on that front,” KiOR said. “When produced at scale with continued development of our technology, we believe that KiOR’s cellulosic biofuel can be cost competitive with other fuels.”

Dale, the Michigan State professor, said KiOR struggles relate more to the circumstances of a single business than to an underlying flaw in the cellulosic technology.

Last year, KiOR had a net loss of $347.5 million on revenue of $1.8 million, and ended the year with more than $224 million in long-term debt.

Its stock has fallen from $20.74 per share in September 2011 to 64 cents Wednesday.

A dump wagon adds freshly gathered corn cobs to a pile on a farm near Hurley, S.D. The first trickle of fuels made from agricultural waste, including corn cobs, is finally winding its way into the nation's energy supply, after years of broken promises and hype promoting a next-generation fuel source cleaner than oil. As refineries produce this so-called cellulosic fuel, it has become clear, even to the industry's allies, that the benefits remain, as ever, years away. (AP Photo/Dirk Lammers, File) less

A dump wagon adds freshly gathered corn cobs to a pile on a farm near Hurley, S.D. The first trickle of fuels made from agricultural waste, including corn cobs, is finally winding its way into the nation's ... more

Photo: DIRK LAMMERS / ap

Image 2 of 21

An ethanol plant stands next to a cornfield near Nevada, Iowa. When President George W. Bush signed a law in 2007 requiring oil companies to add billions of gallons of ethanol to their gasoline each year, he predicted it would make the country "stronger, cleaner and more secure." But the ethanol era has proven far more damaging to the environment than politicians promised and much worse than the government admits today. Government mandates to increase ethanol production have helped drive up corn prices leading to marginal land being farmed to produce the crop. less

An ethanol plant stands next to a cornfield near Nevada, Iowa. When President George W. Bush signed a law in 2007 requiring oil companies to add billions of gallons of ethanol to their gasoline each year, he ... more

Photo: Charlie Riedel / AP

Image 3 of 21

A motorist fills up with gasoline containing ethanol in Des Moines. When President George W. Bush signed a law in 2007 requiring oil companies to add billions of gallons of ethanol to their gasoline each year, he predicted it would make the country "stronger, cleaner and more secure." But the ethanol era has proven far more damaging to the environment than politicians promised and much worse than the government admits today. less

A motorist fills up with gasoline containing ethanol in Des Moines. When President George W. Bush signed a law in 2007 requiring oil companies to add billions of gallons of ethanol to their gasoline each year, ... more

Photo: Charlie Riedel / AP

Image 4 of 21

Algae covers the surface of Corydon Lake in Corydon, Iowa. The ethanol mandate has contributed to millions of acres of new row crops being planted and more fertilizer use. The fertilizer flows downstream, polluting lakes and causing algal blooms. less

Algae covers the surface of Corydon Lake in Corydon, Iowa. The ethanol mandate has contributed to millions of acres of new row crops being planted and more fertilizer use. The fertilizer flows downstream, ... more

Photo: Charlie Riedel / AP

Image 5 of 21

Environmentalist Craig Cox looks at a corn field near Ames, Iowa. The governments predictions of ethanols benefits have proven so inaccurate that independent scientists question whether it will ever achieve its sole environmental goal: reducing greenhouse gases. That makes the hidden costs even more significant. "This is an ecological disaster," said Cox, with the Environmental Working Group, a natural ally of the president that, like others, finds itself at odds with the White House. Higher corn prices due to demand for the crop to produce ethanol has led to more acres planted and stream pollution from fertilizer runoff. less

Environmentalist Craig Cox looks at a corn field near Ames, Iowa. The governments predictions of ethanols benefits have proven so inaccurate that independent scientists question whether it will ever ... more

Photo: Charlie Riedel / AP

Image 6 of 21

Des Moines water works lab technician Bill Blubaugh takes a water sample from the Des Moines River in Des Moines. A mandate to increase ethanol production has resulted in millions of acres of new row crops being planted, in some cases on highly erodible land, helping to increase nitrate pollution in municipal water supplies like Des Moines. less

Des Moines water works lab technician Bill Blubaugh takes a water sample from the Des Moines River in Des Moines. A mandate to increase ethanol production has resulted in millions of acres of new row crops ... more

Photo: Charlie Riedel / AP

Image 7 of 21

Des Moines Water Works lab technician Bill Blubaugh takes a water sample from the Raccoon River in Des Moines. The water works has faced high nitrate levels for many years in the Des Moines and Raccoon Rivers, which supply drinking water to 500,000 people and the mandate to increase ethanol production, with millions of acres of new row crops being planted, is helping to increase nitrate pollution in municipal water supplies like Des Moines. less

Des Moines Water Works lab technician Bill Blubaugh takes a water sample from the Raccoon River in Des Moines. The water works has faced high nitrate levels for many years in the Des Moines and Raccoon Rivers, ... more

Photo: Charlie Riedel / AP

Image 8 of 21

Des Moines water works lab supervisor Jeff Mitchell prepares a water sample for nitrate testing in Des Moines. A mandate to increase ethanol production has resulted in millions of acres of new row crops being planted, in some cases on highly erodible land, helping to increase nitrate pollution in municipal water supplies like Des Moines. less

Des Moines water works lab supervisor Jeff Mitchell prepares a water sample for nitrate testing in Des Moines. A mandate to increase ethanol production has resulted in millions of acres of new row crops being ... more

Photo: Charlie Riedel / AP

Image 9 of 21

Erosion is seen in a cornfield that was recently converted from pasture near Lineville, Iowa. Five million acres of conservation land has been converted to row crops since Obama's ethanol mandate, leading to erosion and pollution from fertilizer runoff. less

Erosion is seen in a cornfield that was recently converted from pasture near Lineville, Iowa. Five million acres of conservation land has been converted to row crops since Obama's ethanol mandate, leading to ... more

Photo: Charlie Riedel / AP

Image 10 of 21

Leroy Perkins stands in his field of grass which is part of the Conservation Reserve Program near Corydon, Iowa. Perkins must decide whether to leave the highly erodible land in grass or break ground for corn production to cash in on high prices caused in part by the ethanol mandate. less

Leroy Perkins stands in his field of grass which is part of the Conservation Reserve Program near Corydon, Iowa. Perkins must decide whether to leave the highly erodible land in grass or break ground for corn ... more

Photo: Charlie Riedel / AP

Image 11 of 21

The Sturgeon Cemetery near Sewal, Iowa stands as an island among corn plants. Forty-four percent of the nation's corn crop in 2012 was used for fuel, about twice the rate seen in 2006, according to the Department of Agriculture. With ethanol production helping to drive up the price of corn and enticing farmers to plant on more and more acres, the cemetery is now surrounded by cornfields with only a primitive trail for access. less

The Sturgeon Cemetery near Sewal, Iowa stands as an island among corn plants. Forty-four percent of the nation's corn crop in 2012 was used for fuel, about twice the rate seen in 2006, according to the ... more

Photo: Charlie Riedel / AP

Image 12 of 21

Erosion is seen in field of soybeans that was recently converted to row crops near Corydon, Iowa. Millions of acres of row crops have been planted on former conservation land because of higher corn prices stemming from a mandate to produce more ethanol. But the ethanol era has proven far more damaging to the environment than politicians promised and much worse than the government admits today. less

Erosion is seen in field of soybeans that was recently converted to row crops near Corydon, Iowa. Millions of acres of row crops have been planted on former conservation land because of higher corn prices ... more

Photo: Charlie Riedel / AP

Image 13 of 21

Wayne County board of supervisors member Billy Joe Alley looks over an eroded cornfield that was recently converted from pasture to row crops near Lineville, Iowa. The once grassy, hilly landscape is made up of fragile soil that, unlike the rest of the state, is poorly suited for corn. "Theyre raping the land, said Alley. Five million acres of conservation land has been converted to row crops since Obama's ethanol mandate, leading to erosion and pollution from fertilizer runoff. less

Wayne County board of supervisors member Billy Joe Alley looks over an eroded cornfield that was recently converted from pasture to row crops near Lineville, Iowa. The once grassy, hilly landscape is made up ... more

Photo: Charlie Riedel / AP

Image 14 of 21

Erosion is seen in field of soybeans that was recently converted to row crops near Corydon, Iowa. The barn is also slated to be demolished to allow more acreage to be planted. Government mandates to increase ethanol production have helped drive up corn prices leading to marginal land being farmed to produce the crop. less

Erosion is seen in field of soybeans that was recently converted to row crops near Corydon, Iowa. The barn is also slated to be demolished to allow more acreage to be planted. Government mandates to increase ... more

Photo: Charlie Riedel / AP

Image 15 of 21

Erosion is seen in a cornfield that was recently converted from pasture near Lineville, Iowa. Five million acres of conservation land has been converted to row crops since President Barack Obama's ethanol mandate, leading to erosion and pollution from fertilizer runoff. In 2012, 44 percent of the nation's corn crop was used for fuel, about twice the rate seen in 2006, according to the Department of Agriculture. less

Erosion is seen in a cornfield that was recently converted from pasture near Lineville, Iowa. Five million acres of conservation land has been converted to row crops since President Barack Obama's ethanol ... more

Photo: Charlie Riedel / AP

Image 16 of 21

A plant that produces ethanol is next to a cornfield near Coon Rapids, Iowa. Government mandates to increase ethanol production have helped drive up corn prices leading to marginal land being farmed to produce the crop. In 2012, 44 percent of the nation's corn crop was used for fuel, about twice the rate seen in 2006, according to the Department of Agriculture. less

A plant that produces ethanol is next to a cornfield near Coon Rapids, Iowa. Government mandates to increase ethanol production have helped drive up corn prices leading to marginal land being farmed to produce ... more

Photo: Charlie Riedel / AP

Image 17 of 21

Erosion is seen in field of soybeans that was recently converted to row crops near Corydon, Iowa. The barn is the distance is also slated to be demolished to allow more acreage to be planted. When President George W. Bush signed a law in 2007 requiring oil companies to add billions of gallons of ethanol to their gasoline each year, he predicted it would make the country "stronger, cleaner and more secure." But the ethanol era has proven far more damaging to the environment than politicians promised and much worse than the government admits today. less

Erosion is seen in field of soybeans that was recently converted to row crops near Corydon, Iowa. The barn is the distance is also slated to be demolished to allow more acreage to be planted. When President ... more

Photo: Charlie Riedel / AP

Image 18 of 21

Leroy Perkins stands in his field of grass which is part of the Conservation Reserve Program near Corydon, Iowa. Perkins must make a decision to either leave the highly erodible field in grass or break ground to plant corn which is at high prices in part because of the ethanol mandate. less

Leroy Perkins stands in his field of grass which is part of the Conservation Reserve Program near Corydon, Iowa. Perkins must make a decision to either leave the highly erodible field in grass or break ground ... more

Photo: Charlie Riedel / AP

Image 19 of 21

The Sturgeon Cemetery near Sewal, Iowa stands as an island among corn plants. With ethanol production helping to drive up the price of corn and enticing farmers to plant on more and more acres, the cemetery is now surrounded by cornfields with only a primitive trail for access. less

The Sturgeon Cemetery near Sewal, Iowa stands as an island among corn plants. With ethanol production helping to drive up the price of corn and enticing farmers to plant on more and more acres, the cemetery is ... more

Photo: Charlie Riedel / AP

Image 20 of 21

Des Moines Waterworks CEO and general manager Bill Stowe talks about dealing with high nitrate levels in the city's water supply in Des Moines. A mandate to increase ethanol production has resulted in millions of acres of new row crops being planted, in some cases on highly erodible land, helping to increase nitrate pollution in municipal water supplies like Des Moines. less

Des Moines Waterworks CEO and general manager Bill Stowe talks about dealing with high nitrate levels in the city's water supply in Des Moines. A mandate to increase ethanol production has resulted in millions ... more